SUPPRESSION OF SPONTANEOUS FIRING IN INFERIOR COLLICULUS NEURONS DURING SOUND PROCESSING

Title

SUPPRESSION OF SPONTANEOUS FIRING IN INFERIOR COLLICULUS NEURONS DURING SOUND PROCESSING

Creator

Voytenko S V; Galazyuk A V

Publisher

Neuroscience

Date

2010
2010-02

Description

Spontaneous activity is a well-known neural phenomenon that occurs throughout the brain and is essential for normal development of auditory circuits and for processing of sounds. Spontaneous activity could interfere with sound processing by reducing the signal-to-noise ratio. Multiple studies have reported that spontaneous activity in auditory neurons can be suppressed by sound stimuli. The goal of this study was to determine the stimulus conditions that cause this suppression and to identify possible underlying mechanisms. Experiments were conducted in the inferior colliculus (IC) of awake little brown bats using extracellular and intracellular recording techniques. The majority of IC neurons (82%) fired spontaneously, with a median spontaneous firing rate of 6 spikes/s. After offset of a 4 ms sound, more than half of these neurons exhibited suppression of spontaneous firing that lasted hundreds of milliseconds. The duration of suppression increased with sound level. Intracellular recordings showed that a short (<50 ms) membrane hyperpolarization was often present during the beginning of suppression, but it was never observed during the remainder of the suppression. Beyond the initial 50 ms period, the absence of significant changes in input resistance during suppression suggests that suppression is presynaptic in origin. Namely, it may occur on presynaptic terminals and/or elsewhere on presynaptic neurons. Suppression of spontaneous firing may serve as a mechanism for enhancing signal-to-noise ratios during signal processing. Published by Elsevier Ltd on behalf of IBRO.

Subject

auditory-nerve fibers; awake animal; awake bats; bat; crossed olivocochlear bundle; electrical-stimulation; frequency modulated sweep; guinea-pigs; hair-cells; intracellular recording; intracellular-recordings; IPSP; Neurosciences & Neurology; nucleus; postsynaptic potentials; signal-to-noise ratio; somatosensory systems; ventral cochlear

Format

Journal Article

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Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

1490-1500

Issue

4

Volume

165

Citation

Voytenko S V; Galazyuk A V, “SUPPRESSION OF SPONTANEOUS FIRING IN INFERIOR COLLICULUS NEURONS DURING SOUND PROCESSING,” NEOMED Bibliography Database, accessed March 29, 2024, https://neomed.omeka.net/items/show/7427.